This is a competing renewal application for a K24 Midcareer Investigator Award in Patient-Oriented Research (POR). The applicant is Eric C. Strain, a physician-researcher in the Department of Psychiatry at Johns Hopkins University School of Medicine. Dr. Strain has devoted his career to POR, and specifically to issues related to research on drug abuse and to treatment of substance abusing patients. His areas of focus have included (among others) the development of medications for the treatment of opioid and cocaine dependence, the testing of medications combined with behavioral treatment interventions, the role of psychiatric symptoms and comorbidity in substance use disorders, the testing of abuse liability of medications, and the special treatment needs of women and men with substance abuse. Over the past five years of funding for this K24, he has also shifted time and effort to the recruitment and development of fellows and junior faculty members who are interested in POR related to substance use disorders. He is in an excellent environment for such work; he is at a major academic research institution (Johns Hopkins), he is a member of a productive research group (the Behavioral Pharmacology Research Unit [BPRU]), and the BPRU has a well-established T32 training program for post-doctoral fellows (directed by Dr. George Bigelow; the candidate is a faculty member of that program, and post-doctoral mentees for this K24 have been enrolled in and supported by the T32 program). The candidate's career goals and objectives are related to the development of a next generation of clinician investigators in addictions-related POR; in addition, the candidate's personal goals are related to his own continued research productivity (which will occur concurrent with his mentoring activities, and facilitate the mentoring process). His immediate goals and objectives relate to the recruitment and development of young clinical investigators who show potential to develop as independently funded investigators committed to POR in addictions. In addition, he has more immediate goals related to continued independent funding and productivity as measured by peer-reviewed papers and scientific presentations, and related to contributions to the broader field of addictions science (e.g., through editing of a journal, and through committee work such as chair of a study section). His longer-term goals relate to the establishment of the next generation of clinician scholars working in the area of addictions at Hopkins, which is expected to be ongoing and to extend beyond the five years of funding that would be provided by this K24. The candidate has the strong backing of his institution and departmental leadership, and is committed to all features of the mentoring process (including his own training as well as the training of mentees in the responsible conduct of research). He has a strong and sustained track record of NIH-funded research, and the past five years of K24 funding show that he has been able to successfully recruit graduating physician residents as well as psychologists and help them begin their clinical research careers. This application provides examples of two research projects; one related to the candidate's own funded work, and the second related to one of his mentee's interests. In summary, the K24 mechanism has been an ideal means for supporting this candidate's research and growth as a clinician investigator and mentor, and continued funding for Dr. Strain will provide continuity and continued growth in the development of a next generation of clinician investigators devoted to patient oriented research in addictions.